Telescopic pump

ABSTRACT

A telescopic pump includes a bellow, a cover and a rod. The bellow includes a first end, a second end and a compressible space in communication with exterior of the bellow via the first end. The cover includes a channel in communication with the first end of the bellow. The rod is connected to the second end of the bellow so that the rod is operable to move the bellow between an extended position and a compressed position. The second end of the bellow is far from the first end of the bellow to enlarge the compressible space to suck fluid into the compressible space in the extended position. The second end of the bellow is close to the first end of the bellow to reduce the compressible space to expel the fluid from the compressible space in the compressed position.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a pump and, more particularly, to a telescopic pump.

2. Related Prior Art

A conventional telescopic pump includes a cylinder, a piston and a rod. The piston is movably inserted in the cylinder. The rod includes an end connected to the piston and another end connected to a handle operable to move the piston to and fro in the cylinder to suck fluid into the cylinder and expel the fluid from the cylinder.

The efficiency of the sucking and expelling of the fluid is closely related to the extent to which the piston is in contact with the cylinder. The efficiency is higher as the contact is tighter. Hence, the piston is always provided with a sealing ring for tight contact with the cylinder.

However, there is considerable friction between the sealing ring and the cylinder, and such friction causes resistance against the movement of the piston relative to the cylinder. Hence, the movement of the piston in the cylinder is difficult. Moreover, the piston is generally made of rubber which is vulnerable to erosion by acid. Such erosion affect the contact of the piston with the cylinder and hence the efficiency of the sucking and expelling of the fluid.

The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.

SUMMARY OF INVENTION

It is the primary objective of the present invention to provide an efficient and reliable telescopic pump.

To achieve the foregoing objective, the telescopic pump includes a bellow, a cover and a rod. The bellow includes a first end, a second end and a compressible space in communication with exterior of the bellow via the first end. The cover includes a channel in communication with the first end of the bellow. The rod is connected to the second end of the bellow so that the rod is operable to move the bellow between an extended position and a compressed position. The second end of the bellow is far from the first end of the bellow to enlarge the compressible space to suck fluid into the compressible space in the extended position. The second end of the bellow is close to the first end of the bellow to reduce the compressible space to expel the fluid from the compressible space in the compressed position.

Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described via detailed illustration of three embodiments referring to the drawings wherein:

FIG. 1 is an exploded view of a telescopic pump according to the first embodiment of the present invention;

FIG. 2 is a perspective view of the telescopic pump shown in FIG. 1;

FIG. 3 is a cross-sectional view of the telescopic pump illustrated in FIG. 2;

FIG. 4 is a cross-sectional view of the telescopic pump in another position than shown in FIG. 3;

FIG. 5 is a partial and cross-sectional view of the telescopic pump according to the second embodiment of the present invention; and

FIG. 6 is a partial and cross-sectional view of the telescopic pump according to the third embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring to FIGS. 1 through 4, a telescopic pump 10 includes a bellow 20, a cover 30, a rod 40, a shell 50, a tubular element 60, a filter 70 and a check valve unit (not numbered) in accordance with a first embodiment of the present invention. The bellow 20 is entirely inserted in the shell 50. The rod 40 is partially inserted in the shell 50. The cover 30 is connected to the shell 50. The cover 30 is further connected to the tubular element 60. The filter 70 is inserted in the cover 30. The check valve unit is also inserted in the cover 30.

The shell 50 includes a front open end 52, a rear open end 54, a window 56 and a scale 58. The shell 50 includes, near the front open end 52, a thread (not numbered). The rear open end 54 is made with an internal diameter smaller than that of the front open end 52. The window 56 is a slot made in the periphery of the shell 50. The window 56 extends in a longitudinal direction of the shell 50. The scale 58 is formed on an external side of the shell 50. The scale 58 is arranged in a longitudinal direction of the shell 50.

The bellow 20 includes an indicator 22, a first end 24, a second end 26 and a compressible space 28. The compressible space 28 is made in the bellow 20 and is in communication with the exterior of the bellow 20 via both of the first end 24 and the second end 26. By printing for example, the indicator 22 is provided on an internal side of the bellow 20, between the first end 24 and the second end 26.

The cover 30 includes a protrusion 31, a transverse connecting portion 33, an external longitudinal connecting portion 37, an internal longitudinal connecting portion (not numbered) and a channel 32. The channel 32 is a T-shaped channel including three open ends 34, 36 and 38. The open end 34 is located between the open ends 36 and 38. The open end 36 is located opposite to the open end 38. The protrusion 31 is a tubular portion extending around a portion of the channel 32 near the open end 36. The transverse connecting portion 33 is a tubular portion extending around a portion of the channel 32 near the open end 34. A thread 35 is formed on an external side of the transverse connecting portion 33. The internal longitudinal connecting portion is a tubular portion extending around a portion of the channel 32 near the open end 38. The external longitudinal connecting portion 37 is an annular portion extending around the internal longitudinal connecting portion.

The internal longitudinal connecting portion of the cover 30 includes a thread (not numbered) engaged with a thread (not numbered) formed at the first end 24 of the bellow 20 to connect the cover 30 to the bellow 20. The open end 38 of the channel 32 is in communication with the first end 24 of the bellow 20 as the cover 30 is connected to the bellow 20.

The external longitudinal connecting portion 37 of the cover 30 includes, on an internal side, a thread (not numbered) engaged with a thread (not numbered) formed on a portion of the shell 50 around the front open end 52. Thus, the external longitudinal connecting portion 37 of the cover 30 is connected to the front open end 52 of the shell 50.

The check valve unit includes two check valves 74. The first check valve 74 is inserted in a portion of the cover 30 in the vicinity of the open end 34 of the channel 32 to allow fluid to enter the telescopic pump 10, but not vice versa. The second check valve 74 is inserted in a portion of the cover 30 near the open end 36 of the channel 32 to allow fluid to leave the telescopic pump 10, but not vice versa.

The rod 40 includes an enlarged end 42 and a reduced end 46. The reduced end 46 of the rod 40 is located opposite to the enlarged end 42. The enlarged end 42 is in the shape of a receptacle that includes a cavity 44 made therein. The wall of the cavity 44 of the enlarged end 42 is formed with a thread engaged with a thread formed on the second end 26 of the bellow 20. A handle 48 is connected to the reduced end 46. Hence, the handle 48 is operable to move the bellow 20 between an extended position and a compressed position via the rod 40. A portion of the rod 40 that extends between the enlarged end 42 and the reduced end 46 is inserted in the rear open end 54 to allow the rod 40 to longitudinally move relative to the shell 50.

The tubular element 60 includes a small portion 62 and a large portion 64. The small portion 62 is made with a diameter smaller than that of the large portion 64. The large portion 64 includes, on an internal side, a thread 66 engaged with the thread 35 to connect the tubular element 60 to the transverse connecting portion 33 in a detachable manner. The small portion 62 of the tubular element 60 is located opposite to the large portion 64. The small portion 62 can be inserted in and hence connected to a pipe or a container (not shown).

The filter 70 is inserted in and located between the tubular element 60 and transverse connecting portion 33. The filter 70 preferably includes an annular flange (not numbered) that extending around a dome (not numbered). The dome of the filter 70 is inserted in the transverse connecting portion 33 via the open end 34. The annular flange of the filter 70 is sandwiched between the large portion 64 and the transverse connecting portion 33.

In use, the handle 48 is operable to move the bellow 20 between an extended position and a compressed position between via the rod 40. In the extended position, the second end 26 of the bellow 20 is far from the first end 24 of the bellow 20 to enlarge the compressible space 28 to suck fluid into the compressible space 28 via the open end 34 of the cover 30.

In the compressed position, the second end 26 of the bellow 20 is close to the first end 24 of the bellow 20 to reduce the compressible space 28 to expel the fluid from the compressible space 28 via the open end 36 of the cover 30.

The change in the volume of the compressible space 28 causes the position of the indicator 22 in the window 56 to change. Hence, the position of the indicator 22 relative to the scale 58 is visible to help a user to determine the volume of the compressible space 28.

It should be noted that the bellow 20 is not in contact with an internal side of the shell 50, i.e., the bellow 20 does not rub against the shell 50 so that there is not friction between the bellow 20 and the shell 50. The operation of the telescopic pump 10 is hence easier than that of a conventional telescopic pump. Moreover, the bellow 20 is made of an acid-resistant material such as Teflon and fluorinated resin to prevent erosion and exhibits a sealing property better than that of a seal.

Referring to FIG. 5, there is a telescopic pump 10 according to a second embodiment of the present invention. The second embodiment is identical to the first embodiment except for two features. Firstly, the channel 32 of the cover 30 does not include the open end 34. That is, the channel 32 includes only the open end 36 and the open end 38. Secondly, the telescopic pump 10 does not include any check valve. Hence, the fluid can travel into and out of the channel 32 of the cover 30 via the open end 36 and the open end 38, without affecting the sucking of the fluid into the bellow 20 in the extended position or the expelling of the fluid from the bellow 20 in the compressed position.

Referring to FIG. 6, there is a telescopic pump 10 according to a third embodiment of the present invention. The third embodiment is identical to the first embodiment except that the protrusion 31 and the cover 30 are two individual elements. Like the tubular element 60, the protrusion 31 is formed with a thread (not numbered) engaged with the thread 35 of the cover 30 so that the channel 32 still includes three open ends. Like the tubular element 60, the protrusion 31 can be made of different sizes and shapes for connection to pipes of different sizes and shapes.

The present invention has been described via the detailed illustration of the embodiments. Those skilled in the art can derive variations from the embodiments without departing from the scope of the present invention. Therefore, the embodiments shall not limit the scope of the present invention defined in the claims. 

1. A telescopic pump comprising: a bellow comprising a first end, a second end and a compressible space in communication with exterior of the bellow via the first end; a cover comprising a channel in communication with the first end of the bellow; and a rod connected to the second end of the bellow so that the rod is operable to move the bellow between an extended position and a compressed position, wherein the second end of the bellow is far from the first end of the bellow to enlarge the compressible space to suck fluid into the compressible space in the extended position, wherein the second end of the bellow is close to the first end of the bellow to reduce the compressible space to expel the fluid from the compressible space in the compressed position.
 2. The telescopic pump according to claim 1, wherein the channel of the cover comprises a first open end in communication with the first end of the bellow.
 3. The telescopic pump according to claim 2, wherein the channel of the cover comprises a second open end via which the channel is in communication with the exterior of the telescopic pump.
 4. The telescopic pump according to claim 2, wherein the channel of the cover comprises a second open end to allow fluid to travel out of the bellow and a third open end to allow the fluid to travel into the bellow.
 5. The telescopic pump according to claim 4, further comprising: a first check valve inserted in the first open end of the channel of the cover to only allow the fluid to travel into the bellow via the first open end; and a second check valve inserted in the second open end of the channel of the cover to only allow the fluid to travel out of the bellow via the second open end.
 6. The telescopic pump according to claim 5, wherein the cover further comprises: a transverse connecting portion extending around a portion of the channel near the open end; and a protrusion extending around a portion of the channel near the second open end.
 7. The telescopic pump according to claim 6, further comprising a tubular element formed with an end connected to the transverse connecting portion of the cover.
 8. The telescopic pump according to claim 7, further comprising a filter inserted in and located between the tubular element and transverse connecting portion.
 9. The telescopic pump according to claim 1, further comprising a handle connected to the rod, opposite to the bellow.
 10. The telescopic pump according to claim 9, wherein the rod comprises a first end connected to the handle and a second end connected to the second end of the bellow.
 11. The telescopic pump according to claim 1, further comprising a shell for containing the bellow.
 12. The telescopic pump according to claim 11, wherein the cover is connected to the shell.
 13. The telescopic pump according to claim 12, wherein the shell comprises a front open end connected to the cover and a rear open end for receiving the rod to guide the rod to move smoothly relative to the shell.
 14. The telescopic pump according to claim 13, wherein the cover comprises a longitudinal connecting portion connected to the front open end of the shell.
 15. The telescopic pump according to claim 11, wherein the shell comprises a window via which the bellow is visible.
 16. The telescopic pump according to claim 15, wherein the shell further comprises a scale near and along the window.
 17. The telescopic pump according to claim 16, wherein the bellow further comprises an indicator visible through the window so that the position of the indicator relative to the scale is used to determine the volume of the compressible space. 